This is an outpatient, double-blind study of patients who heal their gastric or duodenal ulcers after a sever hemorrhage and have document helicobacter pylori infection of the gastric antrum. This is a maintenance study to compare a one time course of antimicrobial therapy (Tetracycline, Metronidazole and Bismuth Subcitrate) for H. Pylori eradication to treatment with a daily histamine 2 receptor antagonist (ranitidine 150 mg BID).